Strange HVAC / blower / fan issue
Discussion
Slightly strange issue with the HVAC blowers in my car (Mk6 Golf)
You can always hear the fans blowing, and changing the speed causes an audible change in the fan speed, but sometimes very little air is actually being blown out of the vents. Changing the fan speed causes the sound of the fan to go up or down, but has little to no effect on how much air comes out. If you turn the system off for 5 minutes or so, the ability of the fans to blow again seems to come back.
Bit of a strange one and a hard one to show a garage as you can guarantee they will always blow when trying to demonstrate it. What could cause this? I'm sure its coincidental, but I have recently had the clutch changed. Is there anything in the vicinity of the clutch that could have been knocked or damaged in the process?
You can always hear the fans blowing, and changing the speed causes an audible change in the fan speed, but sometimes very little air is actually being blown out of the vents. Changing the fan speed causes the sound of the fan to go up or down, but has little to no effect on how much air comes out. If you turn the system off for 5 minutes or so, the ability of the fans to blow again seems to come back.
Bit of a strange one and a hard one to show a garage as you can guarantee they will always blow when trying to demonstrate it. What could cause this? I'm sure its coincidental, but I have recently had the clutch changed. Is there anything in the vicinity of the clutch that could have been knocked or damaged in the process?
Pica-Pica said:
Not quite the same issue, but our Fabia had a heater resistor fail a few years ago. It was blowing at fan speed 4, whatever you turned it to. New resistor needed.
Used to happen on the Astras I drive at work. The resistor would go and the control knob would do nothing unless it was set at "MAX', at which point the blower would come on full blast. Don Roque said:
Pica-Pica said:
Not quite the same issue, but our Fabia had a heater resistor fail a few years ago. It was blowing at fan speed 4, whatever you turned it to. New resistor needed.
Used to happen on the Astras I drive at work. The resistor would go and the control knob would do nothing unless it was set at "MAX', at which point the blower would come on full blast. jimmy156 said:
spikeyhead said:
You've got an issue with your flaps
Ive just adjusting my flaps, and it doesn't seem to make a change! It doesn't blow from anywhere no matter how my flaps are setspikeyhead said:
there are flaps inside your tubes that move air to your feet, or to the screen, or elsewhere. They're controlled by motors when you change the settings, and often go faulty. It's not the ones you twiddle as the air comes out of the dash.
Yeah that’s what I thought you meant. I mean i can change the setting from face to feet to windscreen or any combination, and it doesn’t seem to blow from anywhere. Unless it’s possible they are all closing? And so it’s just buffeting back to the fan?I’m assuming that it wouldn’t be an easy fix if this is the case, as it’s all behind the dash?
jimmy156 said:
Slightly strange issue with the HVAC blowers in my car (Mk6 Golf)
You can always hear the fans blowing, and changing the speed causes an audible change in the fan speed, but sometimes very little air is actually being blown out of the vents. Changing the fan speed causes the sound of the fan to go up or down, but has little to no effect on how much air comes out. If you turn the system off for 5 minutes or so, the ability of the fans to blow again seems to come back.
Bit of a strange one and a hard one to show a garage as you can guarantee they will always blow when trying to demonstrate it. What could cause this? I'm sure its coincidental, but I have recently had the clutch changed. Is there anything in the vicinity of the clutch that could have been knocked or damaged in the process?
I have the same issue in my mk5. It happens on long journeys. After a while (1-2hrs) very little air come out. I think it's one of the servos for airflow direction that closes and then get stuck.You can always hear the fans blowing, and changing the speed causes an audible change in the fan speed, but sometimes very little air is actually being blown out of the vents. Changing the fan speed causes the sound of the fan to go up or down, but has little to no effect on how much air comes out. If you turn the system off for 5 minutes or so, the ability of the fans to blow again seems to come back.
Bit of a strange one and a hard one to show a garage as you can guarantee they will always blow when trying to demonstrate it. What could cause this? I'm sure its coincidental, but I have recently had the clutch changed. Is there anything in the vicinity of the clutch that could have been knocked or damaged in the process?
jimmy156 said:
If it was long journeys I could live with it. It happens after about 10 minutes. Continually cycling between windscreen feet and face seemed to bring it back for a bit.
Anyone know what the fix might be? Would it be a dash out job?
From what I can remember (when I tried to get to the bottom of it several years ago) the servos are accessible if you remove the glove box. The issue was for me that a long journey was required to trigger it so it was an arse ache to try and figure out what was happening. Might be easier for you. Anyone know what the fix might be? Would it be a dash out job?
thebraketester said:
From what I can remember (when I tried to get to the bottom of it several years ago) the servos are accessible if you remove the glove box. The issue was for me that a long journey was required to trigger it so it was an arse ache to try and figure out what was happening. Might be easier for you.
That is really helpful to know, thank you!Mrs Scrump’s car had something similar a few years back.
Turned out to be a blocked cabin filter. My guess was that the fan managed to move air initially but then it was fighting against the blocked filter in trying to pull in fresh air.
Whatever it was, a new cabin filter solved the problem so might be worth checking the filter in your car.
Turned out to be a blocked cabin filter. My guess was that the fan managed to move air initially but then it was fighting against the blocked filter in trying to pull in fresh air.
Whatever it was, a new cabin filter solved the problem so might be worth checking the filter in your car.
I looked at the flaps deep with the dashboard of my bmw using a boroscope, they are cheap to buy and usb ones often can work on a smart phone too. I had a look because I was getting a bit of a pong coming from the vents and it turns out that the easiest way to fix that was to blow hot air a few journeys and it dried it all off. But yeah a boroscope will let you see the flaps moving, at least the ones behind the dash and the side vents.
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